English

Rook decomposition of the Partition function

Combinatorics 2025-07-29 v1 Number Theory

Abstract

The rook numbers are fairly well-studied in the literature. In this paper, we study the max-rook number of the Ferrers boards associated to integer partitions. We show its connections with the Durfee triangle of the partitions. The max-rook number gives a new decomposition of the partition function. We derive the generating functions of the partitions with the Durfee triangle of sizes 33, 44 and 55. We obtain their exact formula and further use it to show the periodicity modulo pp for any pNp \in \mathbb{N} and p2p\geq2. We also establish their parity and parity bias. We give the growth asymptotics of partitions with the Durfee triangle of sizes 33 and 44. We obtain a new rook analogue of the recurrence relation of the partition function.

Keywords

Cite

@article{arxiv.2507.20260,
  title  = {Rook decomposition of the Partition function},
  author = {N. Guru Sharan},
  journal= {arXiv preprint arXiv:2507.20260},
  year   = {2025}
}

Comments

21 pages and 4 figures. Submitted for publication

R2 v1 2026-07-01T04:20:56.473Z